Battery cell, battery cell manufacturing method, battery cell manufacturing system, battery, and electric device

Abstract

The present invention relates to a battery cell, a manufacturing method and system for the same, a battery, and an electric device. The battery cell includes a shell having a wall, an electrode component housed in the shell, a weak portion arranged to break and release pressure when pressure inside the shell reaches a threshold, a main body located within the area surrounded by the weak portion, and a pressure release mechanism provided in the wall, the main body protruding in a direction away from the electrode component relative to the connection portion, and the pressure release mechanism having a first recess formed on the side facing the electrode component at a position corresponding to the main body. The battery cell provided by the present invention can improve the safety of the battery cell.

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and more particularly to battery cells, methods for manufacturing battery cells, systems for manufacturing battery cells, batteries, and electrical devices. [Background technology]

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric planes, electric boats, electric toy cars, electric toy boats, electric toy planes, power tools, etc. Battery cells may include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, etc.

[0003] In the development of battery technology, in addition to improving the performance of battery cells, safety issues have also become a problem that cannot be ignored. If the safety of a battery cell is not ensured, the battery cell cannot be used. Therefore, how to improve the safety of battery cells is a technical problem that needs to be solved urgently in battery technology. Summary of the Invention

[0004] The present invention provides a battery cell, a manufacturing method and system thereof, a battery, and an electric device that can enhance the safety of the battery cell.

[0005] In a first aspect, according to an embodiment of the present invention, there is provided a battery cell comprising: a shell having a wall portion; an electrode component housed in the shell; a weak portion arranged to break and release pressure when the pressure inside the shell reaches a threshold value; a main body portion located within an area surrounded by the weak portion; and a connecting portion located outside the weak portion for connecting the wall portion, and a pressure release mechanism provided on the wall portion, wherein the main body portion protrudes in a direction away from the electrode component relative to the connecting portion, and the pressure release mechanism has a first recess formed on the side facing the electrode component at a position corresponding to the main body portion.

[0006] In the battery cell provided in the embodiment of the present invention, in the above-described aspect, the main body protrudes away from the electrode component relative to the connection portion, causing a sudden change in cross section at the weak portion, resulting in stress concentration at the weak portion. Furthermore, the pressure release mechanism has a first recess formed on the side facing the electrode component at a position corresponding to the main body, which further promotes stress concentration at the weak portion and makes the weak portion more susceptible to cracking. When the pressure inside the shell reaches a threshold value, the pressure is released, ensuring the safety of the battery cell in the event of thermal runaway, which is advantageous for improving the safety and stability of the battery cell when in use.

[0007] In some embodiments, the weakened portion is formed by providing a recessed groove in the pressure release mechanism.

[0008] In the above-described aspect, the recessed groove reduces the thickness of a portion of the pressure release mechanism to form a weakened portion.

[0009] In some embodiments, both the body portion and the connecting portion have a greater thickness than the weakened portion.

[0010] In the above-described aspect, the weak portion has less strength and is more easily broken than the main body portion and the connection portion, so that the battery cell can be pressure-released in a timely manner.

[0011] In some embodiments, when the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1 / B1≦0.5.

[0012] In the above-described embodiment, when the thicknesses of the weak portions and the connection portions are within the above-mentioned numerical ranges, the processing precision of the weak portions can be improved and the uniformity of the thickness of the weak portions can be improved. Therefore, when the weak portions are subjected to alternating stress, the degree of destruction of the weak portions can be made uniform, and the consistency of battery rupture can be improved.

[0013] When W1 / B1<0.1, the thickness of the weak part is relatively thin and the strength is low, so that the weak part is easily broken when the battery cell is not experiencing thermal runaway. Furthermore, when a weak part of this thickness is formed, the size of the weak part varies greatly and the thickness uniformity is poor. When the weak parts of different battery cells are subjected to alternating stresses, the areas or degrees of fatigue or aging may differ, resulting in poor consistency in rupture or pressure release among different battery cells.

[0014] If W1 / B1>0.5, the thickness of the weak part is relatively thick and the strength is high. Therefore, when the preset pressure value of the battery cell is small, the weak part is not easily broken. Therefore, when the battery cell experiences thermal runaway, the gas inside the battery cell cannot be released in a timely manner, and the battery cell is likely to expand, and eventually explode.

[0015] In some embodiments, the recessed groove and the first recess are disposed so that their projections in a first direction perpendicular to the thickness direction of the pressure release mechanism at least partially overlap.

[0016] In the above-described embodiment, the groove and the weak portion are arranged correspondingly in the thickness direction, and the groove and the first recess are arranged so that their projections in the first direction at least partially overlap, thereby promoting stress concentration in the weak portion, making the weak portion more easily broken, and enabling the battery cell to be pressure-released in a timely manner.

[0017] In some embodiments, the connecting portion has a first outer surface and a first inner surface facing the electrode component in the thickness direction of the pressure release mechanism, and the groove is recessed relative to the first inner surface in a direction away from the electrode component and / or the groove is recessed relative to the first outer surface in a direction toward the electrode component.

[0018] In some embodiments, the connecting portion has a first outer surface and a first inner surface facing the electrode component in the thickness direction of the pressure release mechanism, the first recess is recessed relative to the first inner surface in a direction away from the electrode component, and at least a portion of the main body portion protrudes beyond the first outer surface.

[0019] In some embodiments, when the thickness of the connection portion is B1 and the height of the main body portion is H in the thickness direction of the pressure release mechanism, H / B1≦2.

[0020] In the above-described aspect, if the thicknesses of the connection portion and main body portion are within the above-mentioned numerical ranges, the height of the main body portion is appropriate, it is easy to process and mold, and stress concentration at weak portions is promoted, and interference between the main body portion and foreign objects outside the battery cell can be prevented.

[0021] If H / B1>2, the main body is too high, making it difficult to process and mold, and a main body that is too high may protrude onto the surface of the battery cell and interfere with foreign matter outside the battery cell.

[0022] In some embodiments, the first recess has a bottom wall, the first recess recessed from the first inner surface to the bottom wall in a direction away from the electrode component, and the bottom wall does not extend beyond the first outer surface in a direction away from the electrode component.

[0023] In the above-described embodiment, as the distance between the bottom wall and the first outer surface in the thickness direction becomes smaller, the depth of the first recess in the thickness direction becomes deeper, making it easier for stress concentration to form at the connection point between the main body portion corresponding to the position of the first recess and the weak portion, and making it easier for the weak portion to break.

[0024] In some embodiments, the pressure release mechanism further comprises a transition portion that is positioned around the connection portion to connect the wall portion and the connection portion, and that is thicker than the connection portion.

[0025] In the above-described embodiment, the thickness of the transitional portion is relatively thick, thereby increasing the welding strength of the transitional portion and preventing distortion, deformation, burn-through, etc., which may occur during welding due to a small thickness of the transitional portion. Also, the thickness of the connection portion is relatively thin, so that the pressure release mechanism is less likely to crack when subjected to alternating stress, and pressure can be released in a timely manner.

[0026] In some embodiments, where the thickness of the connection portion is B1 and the thickness of the transition portion is B2, B1 / B2≦2 / 3.

[0027] In the above-mentioned embodiment, when the thickness of the joint and transitional portion is within this range, the thickness of the joint and transitional portion is appropriate, and the welding strength of the transitional portion and the strength requirements of the joint can be met.

[0028] In some embodiments, the connecting portion has a first outer surface in a thickness direction of the pressure release mechanism and a first inner surface facing the electrode component, and the transition portion has a second outer surface in a thickness direction of the pressure release mechanism and a second inner surface facing the electrode component, with the second outer surface protruding toward the first outer surface in a direction away from the electrode component and / or the second inner surface protruding toward the electrode component.

[0029] In some embodiments, the body portion projects away from the electrode component relative to the transition portion.

[0030] In the above-described aspect, a step structure is formed between the main body portion, the weak portion, the connection portion and the transition portion, which makes it easy to form stress concentration between the weak portion and the connection portion, particularly promoting stress concentration in the weak portion, making the weak portion more likely to break, and allowing the battery cell to release pressure in a timely manner.

[0031] In some embodiments, the connection portion has a minimum size in a first direction perpendicular to the thickness direction of the pressure release mechanism that is greater than 0.1 mm.

[0032] In the above-described embodiment, the weak portion is closer to the center of the pressure release mechanism, the alternating stresses experienced by the weak portion are more uniform, and the weak portion is more likely to fracture consistently.

[0033] In some embodiments, the battery cell further comprises a protective sheet attached to the outer surface of the wall and covering the pressure release mechanism.

[0034] In the above-described embodiment, the protective sheet can protect the pressure release mechanism and reduce distortion and sink marks that may occur in the pressure release mechanism due to an unexpected collision or damage to the pressure release mechanism by an external object.

[0035] In some embodiments, the shell includes an end cover and a housing, the housing has an opening, the end cover is used to cover the opening, and the wall is the end cover.

[0036] In the above-described embodiment, even if the pressure release mechanism is activated to release a high-temperature, high-pressure substance, the structure of the end cover is not fundamentally affected.

[0037] In a second aspect, the present invention provides a battery including a battery cell according to any one of the embodiments in the first aspect.

[0038] In a third aspect, the present invention provides an electrical device including a battery according to the embodiment of the second aspect, and the battery is used to supply electrical energy.

[0039] In a fourth aspect, according to an embodiment of the present invention, there is provided a method for manufacturing a battery cell, wherein the end cover is provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism includes a first recess formed in a position corresponding to the main body portion, supplying an end cover, supplying an electrode component, supplying a housing having an opening, connecting the electrode component to the electrode terminal, and then connecting the end cover to the housing so as to seal the opening of the housing, wherein the weak portion is arranged to break and release the pressure when the pressure inside the housing reaches a threshold value, the main body portion protruding from the connection portion in a direction away from the electrode component, and the pressure release mechanism has a first recess formed on the side facing the electrode component in a position corresponding to the main body portion.

[0040] In a fifth aspect, according to an embodiment of the present invention, there is provided a battery cell manufacturing system comprising: a first supply device for supplying an end cover provided with a pressure release mechanism and an electrode terminal, wherein the pressure release mechanism includes a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism has a first recess formed in a position corresponding to the main body portion; a second supply device for supplying electrode components; a third supply device for supplying a casing having an opening; a first assembly device for connecting the electrode components to the electrode terminals, and a second assembly device for inserting the electrode components into the casing and then connecting the end cover to the casing so as to seal the opening of the casing, wherein the weak portion is arranged to break and release the pressure when pressure inside the casing reaches a threshold value; the main body portion protruding from the connection portion in a direction away from the electrode component, and the pressure release mechanism has a first recess formed on a side facing the electrode component at a position corresponding to the main body portion.

[0041] In order to more clearly explain the technical solutions according to the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. However, it goes without saying that the accompanying drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other accompanying drawings based on the accompanying drawings without requiring any creative work. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a structural schematic diagram of a vehicle according to an embodiment of the present invention; [Figure 2] 1 is an exploded structural schematic diagram of a battery according to an embodiment of the present invention. [Figure 3] FIG. 3 is a structural schematic diagram of the battery module shown in FIG. 2. [Figure 4] 1 is an exploded structural schematic diagram of a battery cell according to an embodiment of the present invention. [Figure 5] 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention; [Figure 6]FIG. 6 is an enlarged schematic view of A in FIG. 5. [Figure 7] FIG. 2 is an exploded structural schematic diagram of an end cover part of a battery cell according to one embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of the top structure of a pressure release mechanism for a battery cell according to one embodiment of the present invention. [Figure 9] FIG. 10 is a schematic diagram of the top structure of a pressure release mechanism for a battery cell according to another embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view taken along the FF direction in FIG. 9. [Figure 11] 11 is an enlarged schematic view of I in FIG. [Figure 12] FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in an alternative embodiment. [Figure 13] FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in another alternative embodiment. [Figure 14] FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in yet another alternative embodiment. [Figure 15] 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in yet another alternative embodiment. FIG. [Figure 16] 1 is a flowchart of a method for manufacturing a battery cell according to one embodiment of the present invention. [Figure 17] 1 is a schematic block diagram of a battery cell manufacturing system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] In the accompanying drawings, the drawings are not necessarily drawn to scale.

[0044] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings in the embodiments of the present invention, but it is clear that the following embodiments are not all embodiments but only some embodiments of the present invention. Any other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without requiring creative work also fall within the scope of protection of the present invention.

[0045] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. Furthermore, the terms used in the present invention in the specification are intended to describe the purpose of specific embodiments and are not intended to limit the present invention. The terms "comprise," "have," and any variations thereof in the specification, claims, and accompanying drawings of the present invention are intended to cover non-exclusive inclusions. The terms "first," "second," etc. in the specification, claims, and accompanying drawings of the present invention are intended to distinguish between different objects and are not intended to describe a specific order or hierarchy.

[0046] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in combination with the embodiment may be included in at least one embodiment of the present invention. The appearance of the term in each location in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment with respect to other embodiments.

[0047] In the description of the present invention, unless otherwise clearly specified or limited, the terms "attach," "connect," "join," and "attach" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection. It should also be noted that they may refer to a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0048] The term "and / or" in the present invention merely describes the relationship between related objects and indicates that there are three relationships, for example, A and / or B means that A exists alone, A and B exist together, or B exists alone. Also, the symbol " / " in the present invention generally indicates that the related objects before and after it are in an "or" relationship.

[0049] In the embodiments of the present invention, the same reference numerals denote the same elements, and for the sake of brevity, detailed descriptions of the same elements will be omitted in different embodiments. It is understood that the dimensions such as thickness, length, and width of various elements in the embodiments of the present invention shown in the drawings, as well as the dimensions such as thickness, length, and width of the entire integrated device, are merely illustrative and do not imply any limitations on the present invention.

[0050] The term "plurality" as used herein means two or more (including two).

[0051] In the present invention, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries, magnesium ion batteries, etc., and are not limited to these in the embodiments of the present invention. The battery cells may be cylindrical, flat, rectangular, or have other shapes, and are not limited to these in the embodiments of the present invention. Battery cells are classified into cylindrical battery cells, rectangular prismatic battery cells, and soft-pack battery cells based on their packaging type, and are not limited to these in the embodiments of the present invention.

[0052] A battery, as referred to in the embodiments of the present invention, is a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present invention may include a battery module or a battery pack. A battery generally includes a case for packaging one or more battery cells. The case can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0053] A battery cell includes an electrode assembly and an electrolyte, and the electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell operates primarily through the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector, and the current collector without the positive electrode active material layer protrudes onto the current collector with the positive electrode active material layer. The current collector without the positive electrode active material layer is stacked to form a positive electrode tab. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer. The current collectors not coated with the negative electrode active material layer are stacked to form a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon. The material of the separator may be PP (polypropylene) or PE (polyethylene). The electrode component may have a wound structure or a stacked structure, but the embodiment of the present invention is not limited to this.

[0054] The development of battery technology requires simultaneous consideration of many design factors, such as performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge rate, as well as battery safety.

[0055] The pressure release mechanism in a battery cell has a significant impact on battery safety. For example, if a short circuit or overcharging occurs, thermal runaway may occur inside the battery cell, causing a sudden rise in pressure or temperature. In such a situation, the pressure release mechanism operates to release the internal pressure and temperature to the outside, preventing the battery cell from exploding or catching fire.

[0056] A pressure release mechanism is an element or component that operates to release the internal pressure or temperature of a battery cell when the internal pressure or temperature reaches a predetermined threshold. The design of the threshold varies depending on design needs. The threshold may be determined by one or more materials from the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell. The pressure release mechanism may specifically adopt a pressure- or temperature-sensitive element or structure, such as an explosion-proof valve, a gas valve, a pressure release valve, or a safety valve. That is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure release mechanism operates, or a weak structure in the pressure release mechanism breaks, forming an opening or passage for releasing the internal pressure or temperature.

[0057] The term "operation" as used herein refers to the pressure release mechanism being activated or being activated to a certain state, thereby releasing the internal pressure and temperature of the battery cell. The operation of the pressure release mechanism includes, but is not limited to, cracking, fracturing, tearing, or releasing at least a portion of the pressure release mechanism. When the pressure release mechanism is activated, high-temperature and high-pressure materials inside the battery cell are released as a discharge from the operating area. In this way, the pressure or temperature of the battery cell can be controlled, and the battery cell can be released and cooled, thereby preventing the occurrence of a potentially serious accident.

[0058] The emissions from battery cells referred to in this invention include, but are not limited to, electrolyte, dissolved or decomposed positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases produced by reactions, flames, etc.

[0059] After discovering the problem of battery cells not bursting and releasing pressure even when a preset thermal runaway condition is reached during battery cell cycling, the applicant analyzed and researched the structure and operating environment of battery cells. During transportation, temperature changes, or charging and discharging, the internal pressure of a battery cell may alternately increase and decrease, causing the pressure release mechanism to open and close repeatedly, i.e., the pressure release mechanism is subjected to alternating stresses caused by internal gas in the battery cell. The applicant found that when the preset pressure value of a battery cell is low, the strength required for the pressure release mechanism is low. However, to ensure the dimensional accuracy of the pressure release mechanism, the pressure release mechanism must maintain a certain strength. As such, fatigue deformation and fracture are unlikely to occur even when subjected to alternating stresses caused by internal gas in the battery cell. Furthermore, even when the internal pressure of the battery cell exceeds the preset pressure value, the pressure release mechanism does not crack, preventing the battery cell from venting in a timely manner, posing a potential safety issue.

[0060] In view of the above problems discovered by the applicant, the applicant has improved the structure of the battery cell, and the technical solutions described in the embodiments of the present invention are applicable to battery cells, batteries including battery cells, and electrical devices using batteries.

[0061] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop, a boat, an aircraft, an electric toy, a power tool, etc. The vehicle may be a gasoline-powered vehicle, a gas-powered vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range-extending vehicle, etc. The aircraft may be an airplane, a rocket, a space plane, a spaceship, etc. The electric toy may be a stationary or portable electric toy, such as a game console, an electric car toy, an electric boat toy, or an electric plane toy, etc. The power tool may be a metal cutting power tool, a polishing power tool, an assembly power tool, or a railway power tool, such as an electric drill, an electric grinding machine, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, and an electric planer, etc. The embodiment of the present invention is not particularly limited to the above-mentioned electrical equipment.

[0062] In the following embodiments, for convenience of explanation, a vehicle, which is an electric device, will be described as an example.

[0063] 1, a battery 10 is provided inside a vehicle 1. The battery 10 may be provided at the bottom, front, or rear of the vehicle 1. The battery 10 is used to supply electricity to the vehicle 1, and for example, the battery 10 is used as an operational power source for the vehicle 1.

[0064] The vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b controls the battery 10 to supply electricity to the motor 1a to meet the operating electrical needs of the vehicle 1, for example, for starting, navigating, and running.

[0065] In some embodiments of the present invention, the battery 10 may not only serve as the operational power source for the vehicle 1, but may also serve as the driving power source for the vehicle 1, instead of gasoline or natural gas, or in place of part of them, to supply driving force to the vehicle 1.

[0066] 2 and 3, the battery 10 includes a battery cell 30 (not shown in FIG. 2). The battery 10 may further include a case for housing the battery cell 30.

[0067] The case is used to house the battery cells 30 and may be of various construction types.

[0068] In some embodiments, the case may include a bottom shell 11 and a top shell 12. The bottom shell 11 and the top shell 12 are fitted together. The bottom shell 11 and the top shell 12 collectively define a storage space for accommodating the battery cells 30. The bottom shell 11 and the top shell 12 may each have a hollow structure that is open on one side. When the open side of the bottom shell 11 is fitted to the open side of the top shell 12, a case having a storage space is formed. A seal may further be provided between the bottom shell 11 and the top shell 12 to achieve a sealed connection between the bottom shell 11 and the top shell 12.

[0069] In actual application, the bottom shell 11 may be fitted to the ceiling of the top shell 12. The bottom shell 11 is also called an upper case, and the top shell 12 is also called a lower case.

[0070] The bottom shell 11 and the top shell 12 may have various shapes, such as a cylindrical body, a rectangular parallelepiped, etc. In Fig. 2, the bottom shell 11 and the top shell 12 are both rectangular parallelepiped structures, for example.

[0071] The battery 10 may have one or more battery cells 30. If there are multiple battery cells 30, the multiple battery cells 30 may be connected in series, parallel, or series-parallel. The term "series-parallel" refers to the connection of the multiple battery cells 30 being either in series or in parallel. The multiple battery cells 30 may be connected directly in series, in parallel, or in series-parallel, and the entire battery cell set may be housed in a case. Alternatively, the multiple battery cells 30 may be connected in series, in parallel, or in series-parallel in advance to form a battery module 20, and the multiple battery modules 20 may then be further connected together in series, in parallel, or in series-parallel and housed in a case.

[0072] In some embodiments, as shown in Figure 3, the battery includes a plurality of battery cells 30. The plurality of battery cells 30 are previously connected in series, parallel, or series-parallel to form a battery module 20. The plurality of battery modules 20 are then further connected together in series, parallel, or series-parallel and housed in a case.

[0073] In some embodiments, the plurality of battery cells 30 in the battery module 20 are electrically connected to one another by bus members so as to realize parallel, series, or series-parallel configurations of the plurality of battery cells 30 in the battery module 20 .

[0074] As shown in FIG. 4 , in some embodiments, the battery cell 30 includes a shell 40, an electrode component 50, an electrode terminal 60, an insulating member, and an adapter member 70. The shell 40 includes a housing 42 having an opening 421 and an end cover 41. The electrode component 50 is housed in the housing 42 and includes a tab 51. The end cover 41 is used to cover the opening 421. The electrode terminal 60 is attached to the end cover 41. The insulating member is located on the side of the end cover 41 facing the electrode component 50. The adapter member 70 is used to connect the electrode terminal 60 to the tab 51 so as to electrically connect the tab 51 to the electrode terminal 60.

[0075] In particular, the housing 42 may have various shapes, such as a cylindrical body or a rectangular parallelepiped. The shape of the housing 42 is determined depending on the specific shape of the electrode component 50. For example, if the electrode component 50 has a cylindrical structure, the housing 42 may also have a cylindrical structure. If the electrode component 50 has a rectangular parallelepiped structure, the housing 42 may also have a rectangular parallelepiped structure. In FIG. 4, both the housing 42 and the electrode component 50 have a rectangular parallelepiped structure, for example.

[0076] The housing 42 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present invention is not particularly limited thereto.

[0077] There may be one or more electrode components 50 housed in the housing 42. In Figure 4, there are two electrode components 50 housed in the housing 42.

[0078] In some embodiments, the electrode component 50 further includes a positive electrode sheet, a negative electrode sheet, and a separator. The electrode component 50 may have a winding structure in which the positive electrode sheet, the separator, and the negative electrode sheet are formed by winding. The electrode component 50 may also have a layered structure in which the positive electrode sheet, the separator, and the negative electrode sheet are stacked.

[0079] The positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. A separator is positioned between the positive electrode sheet and the negative electrode sheet to separate them so as to reduce the risk of short-circuiting between the positive electrode sheet and the negative electrode sheet.

[0080] Among these, the separator may be made of PP (polypropylene) or PE (polyethylene).

[0081] The tabs 51 of the electrode component 50 are divided into positive tabs and negative tabs. The positive tab may be a portion of the positive electrode current collector that is not coated with the positive electrode active material layer. The negative tab may be a portion of the negative electrode current collector that is not coated with the negative electrode active material layer.

[0082] 4 and 5, in the embodiment of the present invention, the end cover 41 is used to cover the opening 421 of the housing 42 to form a sealed space for accommodating the electrode component 50, and the sealed space may be used to accommodate an electrolyte such as an electrolyte solution. The electrode terminal 60 is an output member for outputting electrical energy from the battery cell 30, and two electrode terminals may be provided.

[0083] The housing 42 may have one or two openings 421. When the housing 42 has one opening 421, the housing 42 may have one end cover 41. When the housing 42 has two openings 421, the housing 42 may have two end covers 41. The two end covers 41 are fitted to cover the two openings 421, respectively, and each end cover 41 may be provided with an electrode terminal 60.

[0084] 4, the housing 42 has one opening 421 and one end cover 41. The end cover 41 may be provided with two electrode terminals 60. One electrode terminal 60 is electrically connected to the positive tab of the electrode component 50 via one adapter member 70. The other electrode terminal 60 is electrically connected to the negative tab of the electrode component 50 via the other adapter member 70.

[0085] In other embodiments, the housing 42 has two openings 421. The two openings 421 are provided on opposite sides of the housing 42, and the housing 42 has two end covers 41. The two end covers 41 are fitted to the two openings 421 of the housing 42, respectively. In such a situation, each end cover 41 may have only one electrode terminal 60. The electrode terminal 60 of one end cover 41 is electrically connected to one tab (positive tab) of the electrode component 50 via one adapter member 70, and the electrode terminal 60 of the other end cover 41 is electrically connected to the other tab (negative tab) of the electrode component 50 via the other adapter member 70.

[0086] 4, the battery cell 30 may further include a pressure release mechanism 80. The pressure release mechanism 80 is attached to the shell 40. The pressure release mechanism 80 is used to release pressure inside the battery cell 30 when the internal pressure or temperature of the battery cell 30 reaches a threshold.

[0087] Illustratively, the pressure relief mechanism 80 may be an explosion-proof valve, an explosion-proof seat, a gas valve, a pressure relief valve, a safety valve, or the like.

[0088] 4-7, in some embodiments, the shell 40 of the present invention includes a wall having a through hole 412 that is covered by the pressure release mechanism 80.

[0089] In an embodiment of the present invention, as shown in Figures 4 to 7, in order for the pressure release mechanism 80 to burst and release pressure at the appropriate time, the embodiment of the present invention provides a battery cell 30 including: a shell 40 having a wall portion; an electrode component 50 housed in the shell 40; a pressure release mechanism 80 provided in the wall portion, the pressure release mechanism 80 including: a weak portion 83 arranged to burst and release pressure when the pressure inside the shell 40 reaches a threshold value; a main body portion 81 located within the area surrounded by the weak portion 83; and a connecting portion 82 located outside the weak portion 83 for connecting the wall portion, wherein the main body portion 81 protrudes in a direction away from the electrode component 50 relative to the connecting portion 82; and the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body portion 81.

[0090] It should be noted that the electrode component 50 in the embodiment of the present invention may be a wound-type electrode component, a laminated-type electrode component, or any other electrode component.

[0091] In some embodiments, the electrode component 50 is a wound-type electrode component. The positive electrode sheet, the negative electrode sheet, and the separator all have a strip-like structure. In an embodiment of the present invention, the positive electrode sheet, the separator, and the negative electrode sheet may be stacked in order and wound two or more times to form the electrode component 50.

[0092] In some other embodiments, the electrode component 50 is a laminated electrode component. Specifically, the electrode component 50 includes a plurality of positive electrode sheets and a plurality of negative electrode sheets, and the positive electrode sheets and the negative electrode sheets are alternately laminated in a direction parallel to the thickness direction of the positive electrode sheets and the thickness direction of the negative electrode sheets.

[0093] In the present invention, the end cover 41 may include a wall, i.e., the pressure release mechanism 80 may be provided on the end cover 41, or the shell 40 may include a wall, i.e., the pressure release mechanism 80 may be provided on the shell 40. It is understood that the pressure release mechanism 80 in the present invention is provided on the wall, and the shell 40 and the pressure release mechanism 80 may be separate structures, i.e., they may be manufactured independently and then assembled by mechanical connection. The shell 40 and the pressure release mechanism 80 may also be a one-piece structure; for example, in the present invention, a predetermined area of ​​the wall may be thinned to form the pressure release mechanism 80. For ease of explanation, the following embodiments will be described as the end cover 41 being a wall.

[0094] The end cover 41 is thicker than the housing 42, and therefore more rigid than the housing 42. The end cover 41 is less likely to deform under the action of the same pressure. Since the internal pressure of the battery cells 30 may alternately increase and decrease during transportation, temperature changes, or charging and discharging, if a pressure release mechanism 80 is provided in the end cover 41, alternating stress acts on the pressure release mechanism 80, activating it to release high-temperature, high-pressure material, and making it less likely that the structure of the end cover 41 will be damaged.

[0095] In the battery cell 30 according to the embodiment of the present invention, the weak portion 83 refers to a portion that is weaker than the main body portion 81 and the connection portion 82 in the pressure release mechanism 80 and is more likely to crack, fracture, tear, or open. The pressure release mechanism 80 includes the weak portion 83, the main body portion 81, and the connection portion 82, and the weak portion 83 is located at the connection between the main body portion 81 and the connection portion 82. It is understood that a predetermined region of the pressure release mechanism 80 is thinned, the thinned portion forms the weak portion 83, and the two portions separated by and connected by the weak portion 83 form the main body portion 81 and the connection portion 82. Alternatively, material processing is performed on a predetermined region of the pressure release mechanism 80, making the region weaker in strength than the other regions, so that the weak portion 83 forms the weak portion 83, and the two strong portions separated by and connected by the weak portion 83 form the main body portion 81 and the connection portion 82.

[0096] The connection portion may be directly connected to the wall portion, or may be indirectly connected to the wall portion via another portion.

[0097] In some instances, the weakened portion may wrap around the body portion once. In other instances, the weakened portion may wrap around the body portion an angle, for example, the weakened portion may wrap around the body portion 180°-300°.

[0098] When the preset pressure value of the battery cell 30 is small, the strength required for the weak portions 83 is low. However, to ensure the dimensional accuracy of the weak portions 83, it is necessary to maintain a certain strength for the weak portions 83. During transportation, temperature changes, or charging / discharging of the battery cell 30, the internal pressure of the battery cell 30 may alternately increase and decrease. This may cause the pressure release mechanism 80 to deform by swelling away from the electrode component 50 or by sinking toward the electrode component 50. When the pressure release mechanism 80 alternates between swelling and sinking, the weak portions 83 connected to the main body 81 and the connecting portion 82 are subjected to alternating stresses. Therefore, it is necessary to maintain a certain strength for the weak portions 83 to prevent them from cracking due to the action of the alternating stresses. However, because the weak portions 83 have a certain strength, if the internal pressure of the battery cell 30 exceeds a preset pressure value, the weak portions 83 may not crack in a timely manner. The internal pressure of the battery cell 30 is too high, and the gas inside the battery cell 30 is not released in a timely manner, which may cause the battery cell 30 to expand and even explode.

[0099] In the battery cell 30 according to the embodiment of the present invention, the main body 81 protrudes relative to the connecting portion 82 in a direction away from the electrode component 50, causing a sudden change in cross section at the weak portion 83, resulting in stress concentration at the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81, which further promotes stress concentration at the weak portion 83 and makes the weak portion 83 more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold value, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway, and is advantageous in improving the safety and stability of the battery cell 30 in use.

[0100] In some embodiments, the battery cell 30 further includes a protective sheet 90. The protective sheet 90 is attached to the outer surface of the wall of the shell 40 and covers the pressure release mechanism 80.

[0101] The protective sheet 90 can protect the pressure release mechanism 80 and reduce the possibility that an unexpected collision or damage to the pressure release mechanism 80 by an external object will cause the pressure release mechanism 80 to be distorted, deformed, or form a sink mark, which will further affect the normal rupture and explosion of weak parts 83 of the pressure release mechanism 80.

[0102] In some examples, the protective sheet 90 is positioned on top of the end cover to cover the through holes 412. The material of the protective sheet 90 may be a plastic such as polyethylene or polypropylene.

[0103] In the battery cell 30 according to the embodiment of the present invention, the weak portions 83 may have a shape such as a curved structure or a ring structure. When the weak portions 83 have a curved structure or a ring structure, the main body portions 81 are located in the area surrounded by the weak portions 83, the connecting portions 82 are located outside the weak portions 83, and the connecting portions 82 are used to connect the wall portions of the shell 40.

[0104] In some embodiments, weakened portion 83 may be formed by forming a notch, groove, or other structure in pressure release mechanism 80 to reduce the strength of a portion of pressure release mechanism 80 .

[0105] 8 to 15 , the weakened portion 83 is formed by providing a recessed groove 83c in the pressure release mechanism 80. The connecting portion 82 has a first outer surface 82a and a first inner surface 82b in the thickness direction X of the pressure release mechanism 80, and the first inner surface 82b faces the electrode component 50.

[0106] For example, the grooves 83c may be formed by removing material from the pressure release mechanism 80 by machining, which is advantageous in reducing processing costs and difficulty. In the thickness direction X, the weak portions 83 and the grooves 83c are located in correspondence with each other.

[0107] 8, the recessed grooves 83c in the pressure release mechanism 80 are curved, and the weak portions 83 corresponding to the recessed grooves 83c have a curved structure. Alternatively, the recessed grooves 83c in the pressure release mechanism 80 are linear, and the weak portions 83 corresponding to the recessed grooves 83c have a linear structure.

[0108] When the internal pressure of the battery cell 30 alternately changes from high to low, the weak part 83 is prone to fatigue aging and breakage, and the main body part 81 reverses after the weak part 83 breaks, thereby releasing the pressure from the battery cell 30.

[0109] 9, the recessed groove 83c in the pressure release mechanism 80 is annular. The weak portion 83 corresponding to the recessed groove 83c is also annular. The main body portion 81 is located in the area surrounded by the weak portion 83. The connecting portion 82 is used to connect the wall portions.

[0110] In some examples, the area surrounded by the groove 83c may be racetrack-shaped, circular, rectangular, or elliptical. When the internal pressure of the battery cell 30 alternately rises and falls, the weak portion 83 is prone to fatigue aging and breakage. When the weak portion 83 breaks, the through-hole 412 in the wall is exposed, allowing the battery cell 30 to communicate with the external environment and quickly release pressure.

[0111] In some embodiments, the recessed groove 83c is recessed along the thickness direction X.

[0112] In some examples, as shown in FIGS. 10 and 11, the recessed groove 83c is recessed in a direction toward the electrode component 50 relative to the first outer surface 82a.

[0113] In some other examples, as shown in FIG. 12, the recessed groove 83c is recessed in a direction away from the electrode component 50 relative to the first inner surface 82b.

[0114] In another example, as shown in Figure 13, there are two grooves 83c, one of which is recessed in a direction away from the electrode part 50 relative to the first inner surface 82b, and the other groove 83c is recessed in a direction toward the electrode part 50 relative to the first outer surface 82a.

[0115] 14, both the main body portion 81 and the connection portion 82 are thicker than the weak portion 83. The weak portion 83 has less strength than the main body portion 81 and the connection portion 82 and is more easily broken, so that the battery cell 30 can be pressure-released in a timely manner if the battery cell experiences thermal runaway.

[0116] In some embodiments, where the thickness of connecting portion 82 is B1 and the thickness of weak portion 83 is W1, the relationship 0.1≦W1 / B1≦0.5 holds. When the thicknesses of weak portion 83 and connecting portion 82 are within the above ranges, the processing precision of weak portion 83 can be improved, thereby improving the uniformity of the thickness of weak portion 83. When weak portion 83 is subjected to alternating stress, the degree of destruction of weak portion 83 is uniform, thereby improving the consistency of battery rupture.

[0117] If W1 / B1<0.1, the thickness of the weak portion 83 is relatively thin and the strength of the weak portion 83 is low, making the weak portion 83 prone to fracture when the battery cell 30 is not experiencing thermal runaway. Furthermore, when forming weak portions 83 of this thickness, the size of the weak portions 83 varies greatly and the thickness uniformity is poor. If the weak portions 83 of different battery cells 30 are subjected to alternating stresses, the areas or degrees of fatigue or aging may differ, resulting in poor consistency in rupture or pressure release among different battery cells 30.

[0118] When W1 / B1>0.5, the thickness of the weak portion 83 is relatively thick and the strength of the weak portion 83 is high. Therefore, when the preset pressure value of the battery cell 30 is small, the weak portion 83 is not easily broken. Therefore, when the battery cell 30 experiences thermal runaway, the gas inside the battery cell 30 cannot be released in a timely manner, and the battery cell 30 is likely to expand, which may eventually cause an explosion or the like.

[0119] 14 , in the battery cell 30 according to the embodiment of the present invention, the first recess 84 is recessed relative to the first inner surface 82b in a direction away from the electrode component 50. Stress concentration occurs at the weak portion 83, and the weak portion 83 is easily broken, allowing pressure to be released from the battery cell 30 in a timely manner.

[0120] In some embodiments, the groove 83c and the first recess 84 are arranged so that their projections in a first direction Y perpendicular to the thickness direction X of the pressure release mechanism 80 at least partially overlap. The groove 83c and the weak portion 83 are arranged correspondingly in the thickness direction X, and the groove 83c and the first recess 84 are arranged so that their projections in the first direction Y at least partially overlap, which promotes stress concentration in the weak portion 83 and makes the weak portion 83 more easily broken, thereby enabling pressure release of the battery cell 30 in a timely manner.

[0121] 14 , the first recess 84 is recessed relative to the first inner surface 82b in a direction away from the electrode component 50, and at least a portion of the main body 81 protrudes toward the first outer surface 82a. At least a portion of the main body 81 protrudes toward the first outer surface 82a, forming a stepped structure between the main body 81 and the connecting portion 82, which significantly improves stress at the connection point between the main body 81 and the connecting portion 82, and since the weak portion 83 is located at the connection point between the main body 81 and the connecting portion 82, stress concentration at the weak portion 83 is promoted.

[0122] 14 , in the thickness direction X of the pressure release mechanism 80, if the thickness of the connecting portion 82 is B1 and the height of the main body portion 81 is H, then H / B1≦2. When the thicknesses of the connecting portion 82 and the main body portion 81 are within the above ranges, the height of the main body portion 81 is appropriate, it is easy to process and mold, and stress concentration at the weak portion 83 is promoted, and interference between the main body portion 81 and foreign matter outside the battery cell 30 can be prevented.

[0123] If H / B1>2, the height of the main body 81 is too high and difficult to process, and a main body 81 that is too high may protrude from the surface of the battery cell 30 and interfere with foreign matter outside the battery cell 30.

[0124] 14 , the first recess 84 has a bottom wall 841, and is recessed from the first inner surface 82b to the bottom wall 841 in a direction away from the electrode component 50, and the bottom wall 841 does not extend beyond the first outer surface 82a in the direction away from the electrode component 50. As the distance between the bottom wall 841 and the first outer surface 82a in the thickness direction X decreases, the recession of the first recess 84 in the thickness direction X becomes deeper, which makes it easier to form stress concentrations at the connection points between the main body portion 81 corresponding to the positions of the first recess 84 and the weak portions 83, and makes it easier for the weak portions 83 to break.

[0125] In some embodiments, the pressure release mechanism 80 of the present invention further includes a transitional portion 85. As shown in FIG. 14 , the transitional portion 85 is disposed around the connecting portion 82 to connect the wall portion and the connecting portion 82, and the transitional portion 85 is thicker than the connecting portion 82. The relatively thicker transitional portion 85 increases the welding strength of the transitional portion 85 and prevents distortion, deformation, or burn-through during welding due to a small thickness of the transitional portion 85. Furthermore, the relatively thin connecting portion 82 prevents the pressure release mechanism 80 from cracking easily when subjected to alternating stress, allowing for timely pressure release.

[0126] In some embodiments, if the thickness of connection portion 82 is B1 and the thickness of transition portion 85 is B2, then B1 / B2≦2 / 3. If the thicknesses of connection portion 82 and transition portion 85 are within this range, the thicknesses of connection portion 82 and transition portion 85 are appropriate, and both the weld strength of transition portion 85 and the strength requirements of connection portion 82 can be met.

[0127] It should be noted that the transition portion 85 has a second outer surface 85a and a second inner surface 85b in the thickness direction X of the pressure release mechanism 80, and the second inner surface 85b faces the electrode component 50.

[0128] In some embodiments, the second outer surface 85a protrudes beyond the first outer surface 82a in a direction away from the electrode component 50.

[0129] In some embodiments, in a direction toward the electrode component 50, the second inner surface 85b protrudes beyond the first inner surface 82b.

[0130] In some embodiments, the second outer surface 85a protrudes beyond the first outer surface 82a in a direction away from the electrode component 50, and the second inner surface 85b protrudes beyond the first inner surface 82b in a direction toward the electrode component 50.

[0131] For example, if the thickness of connection portion 82 is B1 and the thickness of transition portion 85 is B2, then B1 / B2≦2 / 3. If the thicknesses of connection portion 82 and transition portion 85 are within this range, the thicknesses of connection portion 82 and transition portion 85 are appropriate, and both the welding strength of transition portion 85 and the tear strength of connection portion 82 can be satisfied.

[0132] In some embodiments, the transition portion 85 and the connecting portion 82 are connected with a smooth transition, which prevents the connection between the transition portion 85 and the connecting portion 82 from breaking during the installation process.

[0133] 15 , in the thickness direction X, the main body portion 81 protrudes away from the electrode component 50 relative to the transition portion 85. The transition portion 85 is thicker than the connection portion 82. A step structure is formed between the main body portion 81, the weak portion 83, the connection portion 82, and the transition portion 85, which tends to cause stress concentration between the weak portion 83 and the connection portion 82, particularly promoting stress concentration at the weak portion 83, which makes the weak portion 83 more likely to break, and allows the battery cell 30 to release pressure in a timely manner.

[0134] In the embodiment of the present invention, the minimum size of the connecting portion 82 in the first direction Y is greater than 0.1 mm. The weak portion 83 is closer to the center position of the pressure release mechanism 80, so that the alternating stresses received by the weak portion 83 are more uniform, and the weak portion 83 is more likely to break.

[0135] As shown in FIG. 16, an embodiment of the present invention is a method for manufacturing a battery cell 30,

[0136] supplying an end cover (41) provided with a pressure release mechanism (80) and an electrode terminal (60), the pressure release mechanism (80) including a weak portion (83), a main body portion (81) located in an area surrounded by the weak portion (83), and a connecting portion (82) located outside the weak portion (83) for connecting the end cover (41), the main body portion (81) protruding from the connecting portion (82), and the pressure release mechanism (80) having a first recess (84) formed at a position corresponding to the main body portion (81);

[0137] Providing an electrode component 50;

[0138] providing a housing 42 having an opening 421;

[0139] connecting the electrode component 50 to the electrode terminal 60;

[0140] and then inserting the electrode assembly 50 into the housing 42 and then connecting the end cover 41 to the housing 42 so as to close the opening 421 of the housing 42;

[0141] The weak portion (83) is arranged to break and release the pressure when the pressure inside the housing (42) reaches a threshold value, the main body (81) protrudes in a direction away from the electrode part (50) relative to the connection part (82), and the pressure release mechanism (80) has a first recess (84) formed on the side facing the electrode part (50) at a position corresponding to the main body (81).

[0142] In a battery cell 30 manufactured by the manufacturing method for a battery cell 30 according to an embodiment of the present invention, the main body 81 of the pressure release mechanism 80 protrudes away from the electrode component 50 relative to the connection portion 82, causing stress concentration at the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81, which promotes stress concentration at the weak portion 83, reduces the strength of the weak portion 83, and makes the weak portion 83 more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold value, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway, which is advantageous in improving the safety and stability of battery use.

[0143] The battery cell 30 according to the above-described embodiment can be manufactured by the method for manufacturing the battery cell 30 according to the embodiment of the present invention.

[0144] As shown in FIG. 17 , an embodiment of the present invention further provides a battery cell 30 manufacturing system 1000,

[0145] a first supply device (1001) for supplying an end cover (41) provided with a pressure release mechanism (80) and an electrode terminal (60), the pressure release mechanism (80) including a weak portion (83), a main body portion (81) located in an area surrounded by the weak portion (83), and a connecting portion (82) located outside the weak portion (83) for connecting the end cover (41), the main body portion (81) protruding from the connecting portion (82), and the pressure release mechanism (80) having a first recess (84) formed at a position corresponding to the main body portion (81);

[0146] a second supply device 1002 for supplying the electrode component 50;

[0147] a third supply device 1003 for supplying a housing 42 having an opening 421;

[0148] a first assembly device 1004 for connecting the electrode component 50 to the electrode terminal 60;

[0149] a second assembly device 1005 for inserting the electrode component 50 into the housing 42 and then connecting the end cover 41 to the housing 42 so as to close the opening 421 of the housing 42;

[0150] A manufacturing system (1000) for a battery cell (30) is provided, in which a weak portion (83) is arranged to break and release the pressure when the pressure inside the housing (42) reaches a threshold value, a main body portion (81) protrudes in a direction away from the electrode component (50) relative to the connection portion (82), and a first recess portion (84) is formed in the pressure release mechanism (80) on the side facing the electrode component (50) at a position corresponding to the main body portion (81).

[0151] In the manufacturing system 1000 for the battery cell 30 according to the embodiment of the present invention, the main body 81 of the pressure release mechanism 80 protrudes away from the electrode component 50 relative to the connection portion 82, causing stress concentration at the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81, thereby promoting stress concentration at the weak portion 83, reducing the strength of the weak portion 83 and making the weak portion 83 more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold value, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway, and advantageously improving the safety and stability of battery use.

[0152] The manufacturing method of the battery cell 30 according to the embodiment described above can be carried out by the manufacturing system of the battery cell 30 according to the embodiment of the present invention.

[0153] Although the present invention has been described with reference to preferred embodiments, various modifications may be made and elements may be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural contradiction, the technical features recited in each embodiment may be combined in any manner. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions encompassed by the claims. [Explanation of symbols]

[0154] X thickness direction Y Primary Direction 1 vehicle 1a motor 1b Controller 10 batteries 11 Bottom shell 12 Top Shell 20 batteries 30 battery cells 40 shells 41 End cover 42 Case 421 Aperture 412 through hole 50 Electrode parts 51 tabs 60 electrode terminal 70 Adapter parts 80 Pressure release mechanism 81 Main body 82 Connection 82a First outer surface 82b First inner surface 83 Weak part 83c concave groove 84 First recess 841 Bottom wall 85 Transient part 85a Second outer surface 85b second inner surface

Claims

1. a shell having a wall; an electrode component housed in the shell; a pressure release mechanism provided in the wall portion, the pressure release mechanism including a weak portion arranged to be broken to release the pressure when the pressure inside the shell reaches a threshold value, a main body portion located within an area surrounded by the weak portion, and a connecting portion located outside the weak portion for connecting the wall portion; Equipped with the main body portion protrudes from the connection portion in a direction away from the electrode component, the pressure release mechanism has a first recess formed at a position corresponding to the main body portion on a side facing the electrode component, the weakened portion is formed by providing a recessed groove in the pressure release mechanism, the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion; When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1 / B1≦0.5 is satisfied, In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H / B1≦2. Battery cell.

2. the recessed groove and the first recess are provided so that projections of the recessed groove and the first recess in a first direction perpendicular to the thickness direction of the pressure release mechanism at least partially overlap with each other. The battery cell according to claim 1 .

3. the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component; the recessed groove is recessed relative to the first inner surface in a direction away from the electrode component and / or is recessed relative to the first outer surface in a direction toward the electrode component; The battery cell according to claim 1 or 2.

4. the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component; the first recess is recessed relative to the first inner surface in a direction away from the electrode component; At least a portion of the main body protrudes from the first outer surface. The battery cell according to any one of claims 1 to 3.

5. the first recess has a bottom wall, and the first recess is recessed from the first inner surface to the bottom wall in a direction away from the electrode component; the bottom wall does not extend beyond the first outer surface in a direction away from the electrode component; The battery cell according to claim 4 .

6. the pressure release mechanism further includes a transition portion provided around the connection portion for connecting the wall portion and the connection portion, the transition portion having a thickness greater than that of the connection portion. The battery cell according to any one of claims 1 to 5.

7. When the thickness of the connection portion is B1 and the thickness of the transition portion is B2, B1 / B2≦2 / 3. The battery cell according to claim 6 .

8. the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component; the transition portion has a second outer surface and a second inner surface in a thickness direction of the pressure release mechanism, the second inner surface facing the electrode component; the second outer surface projects toward the first outer surface in a direction away from the electrode part, and / or the second inner surface projects toward the first inner surface in a direction toward the electrode part. The battery cell according to claim 6 or 7.

9. the main body portion protrudes in a direction away from the electrode component relative to the transition portion; The battery cell according to any one of claims 6 to 8.

10. a minimum size of the connecting portion in a first direction perpendicular to a thickness direction of the pressure release mechanism is greater than 0.1 mm; The battery cell according to any one of claims 6 to 9.

11. The battery cell further includes a protective sheet attached to an outer surface of the wall portion and covering the pressure release mechanism. The battery cell according to any one of claims 1 to 10.

12. The shell includes an end cover and a housing, the housing has an opening, and the end cover is used to cover the opening; The wall portion is the end cover. The battery cell according to any one of claims 1 to 11.

13. A battery comprising the battery cell according to any one of claims 1 to 12.

14. 14. An electrical device comprising the battery of claim 13 for supplying electrical energy.

15. supplying an end cover, the end cover being provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism having a first recess formed at a position corresponding to the main body portion; Providing an electrode component; providing an enclosure having an opening; connecting the electrode component to the electrode terminal; inserting the electrode component into the housing and then connecting the end cover to the housing so as to close the opening of the housing; Including, the weakened portion is arranged to break and release pressure when a pressure inside the housing reaches a threshold; the main body portion protrudes from the connection portion in a direction away from the electrode component, the pressure release mechanism has the first recess formed at a position corresponding to the main body portion on a side facing the electrode component, the weakened portion is formed by providing a recessed groove in the pressure release mechanism, the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion; When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1 / B1≦0.5 is satisfied, In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H / B1≦2. Battery cell manufacturing method.

16. a first supply device for supplying an end cover, the end cover being provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism having a first recess formed at a position corresponding to the main body portion; a second supply device for supplying the electrode component; a third supply device for supplying an enclosure having an opening; a first assembly device for connecting the electrode component to the electrode terminal; a second assembly device for inserting the electrode component into the housing and then connecting the end cover to the housing so as to close the opening of the housing; Equipped with the weakened portion is arranged to break and release pressure when a pressure inside the housing reaches a threshold; the main body portion protrudes from the connection portion in a direction away from the electrode component, the pressure release mechanism has the first recess formed at a position corresponding to the main body portion on a side facing the electrode component, the weakened portion is formed by providing a recessed groove in the pressure release mechanism, the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion; When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1 / B1≦0.5 is satisfied, In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H / B1≦2. Battery cell manufacturing system.

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